1. School of Information Science, JAIST, Asahidai 1-1, Nomi, Ishikawa 923-1292, Japan
2. Computational Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
3. Research Center for Advanced Computing Infrastructure, JAIST, Asahidai 1-1, Nomi, Ishikawa 923-1292, Japan